1. Field of the Invention
This invention pertains to sea mine training devices, and more particularly to such devices which respond to the proximate presence of a large object by releasing a visible signal.
2. Description of the Prior Art
Prior mine simulators have utilized a number of service mine components so as to duplicate service mine response to a given target object. Such mine simulators are bulky, including large casings which must be weighted with inert material for negative buoyancy. Since these simulators are often planted from aircraft or from the sides of ships as are real mines, the final mine placement on the sea floor is not exact.
U.S. Pat. No. 3,709,148 issued to Costley et al. discloses a drill mine which has the same operational and physical characteristics as a service mine. The Costley et al. mine is provided with apparatus for indicating mine actuation, and for facilitating retrieval thereof. U.S. Pat. No. 2,949,853 issued to C. C. Vogt discloses another prior mine simulator which releases a tethered float which includes a smoke signal to indicate actuation of the mine simulator. U.S. Pat. No. 3,086,464 issued to F. E. Butler et al. discloses a detachable practice mine section, which, upon activation releases a float, after a predetermined delay, which in turn activates a visible signal indicating actuation of the mine simulator and also the location thereof. U.S. Pat. No. 2,912,929 issued to R. D. Mattingly et al. discloses a submarine drill mine particularly suited for planting in shallow water. When actuated, a surface signal is produced, comprising a charge of chemical which upon reaction with water, forms a gas which in turn spontaneously ignites when exposed to oxygen in the atmosphere at the surface of the water to form a bright flame and large volume of smoke. Each of these U.S. Patents should be studied to gain an appreciation for the scope of the prior art.